Early twin studies of adult individuals have found a heritability of IQ between 57% and 73%, with some recent studies showing heritability for IQ as high as 80%.
But genetics can explain the wide range of possible IQs too because so many different genes are involved in developing and running a brain. It is possible, for example, to inherit all the higher IQ genes from each parent and leave the lower IQ ones behind. Now the child will be brighter than the parent.
Is Being a Genius Inherited?/Heritability of IQ. According to studies, genetics can drive anywhere between 30-75% of the variations in people's IQ levels. However, certain environmental factors and socioeconomic status can prevent a person from achieving their true genetic potential of IQ levels.
Intelligence types and levels are partially hereditary, in that certain neural pathways can tend to develop in response to inherited characteristics. They are also strongly impacted by the environment. Both heredity and environment are important for generating the best levels of intelligence in your areas of interest.
Is Intelligence Inherited? General intelligence definitely runs in the family. Twin studies (on both identical twins and fraternal twins) have found a heritability of IQ between 57% and 73%, and in some cases, even higher.
30-75% of variations in IQ levels could be due to genes, and multiple genes play a role in determining the intelligence potential of the individual. However, environmental factors may influence how much of the genetic potential the person achieves during the lifetime.
Genetic factors accounted for 85% of the variation in Verbal IQ and 69% of Performance IQ. The remainder was accounted for by nonshared environment. There were no significant effects of shared environment.
Studies of twins do in fact provide strong evidence for the heritability of intelligence; the scores of identical twins reared apart are highly correlated. In addition, adopted children's scores are highly correlated with their birth parents and not with their adoptive parents.
Developmental research. One of the most interesting developmental findings about intelligence is that its heritability as estimated in twin studies increases dramatically from infancy (20%) to childhood (40%) to adulthood (60%), while age-to-age genetic correlations are consistently high43,44.
There is no one “IQ gene,” but the study, published in Nature Genetics, is precise enough to determine that there are at least 22 specific genes related to intelligence. The researchers analyzed intelligence test scores and the complete genomes of over 78,000 people.
Although there is no direct evidence for the genetic basis of genius or creativity, one factor deserves distinct consideration, particularly with respect to science—intelligence has indirectly been shown to have strong genetic transmission.
But geniuses require to be a bit crazy, yet also do prolonged focused work – and this is a reason why there are so few of them. So – high intelligence is very rare (and some societies have too low an average intelligence to generate more than a tiny proportion of very intelligent people).
There's a big difference between being really smart and being a genius. While geniuses tend to be exceptionally intelligent, they also use imagination and creativity to invent, discover or create something new within their field of interest.
Although IQ differences between individuals have been shown to have a large hereditary component, it does not follow that disparities in IQ between groups have a genetic basis.
Intelligence is also strongly influenced by the environment. During a child's development, factors that contribute to intelligence include their home environment and parenting, education and availability of learning resources, and healthcare and nutrition.
Empirical evidence suggests that especially parental education, parental income, and maternal IQ are important predictors of intelligence.
We also have some genes in small structures in the cell called mitochondria. Mitochondria are sometimes called the power plants of the cell: they work on molecules to make them ready to give us the energy we need for our body functions. The mitochondrial genes always pass from the mother to the child.
💡 Eye color and height can be inherited from fathers due to the complex interplay of dominant and recessive genes. 💡 Other characteristics, ranging from physical traits like dimples and lip structure to traits like sneezing and fingerprint patterns, may also have genetic links.
These studies showed that IQ is very heritable (although the environment still plays a role in determining your IQ). We can tell this because the IQ of identical twins are almost always the same and non-identical twins are only sometimes the same.
The single strongest predictor of a person's IQ is the IQ of his or her mother. Also interesting: However, once you get beyond the school environment, it's not a very reliable predictor of performance. Controlling for other factors, people with high IQs do not have better relationships and better marriages.
Often, this term is used in reference to the resemblance between parents and their offspring. In this context, high heritability implies a strong resemblance between parents and offspring with regard to a specific trait, while low heritability implies a low level of resemblance.
The findings suggested that the heritability of each personality trait was 53% for extraversion, 41% for agreeableness, 44% for conscientiousness, 41% for neuroticism, and 61% for openness.
Evidence of Genetic Influences on Intelligence
Studies show that IQ scores of identical twins may be more similar than those of fraternal twins. Siblings who were raised together in the same environment have more similar IQs than those of adopted children who were brought up in the same household.
Similarly to brain volume, global grey matter volume is positively associated with intelligence. More specifically, higher intelligence has been associated with larger cortical grey matter in the prefrontal and posterior temporal cortex in adults.